Automatic coffee makers are found in many places in modem society. Particularly, they are found in large offices, restaurants, coffee shops, donut shops, and the like. Moreover, other automatic brewing apparatus than automatic coffee makers are found in such places as noted above, which other brewing apparatus is employed to brew tea, which may be served as either hot tea or iced tea, or to make a soup which may essentially be brewed using specially prepared soup concentrates. Any such brewed product which is made in batches by apparatus in keeping with the present invention will be termed to be a "brewed beverage". It will also be understood that, for the most part, it is coffee that will be particularly the brewed beverage which is to be made in apparatus in keeping with the present invention, but the following discussion is not limited to coffee brewers per se.
There are still many automatic coffee brewers in use which have electromechanical thermostats. They are set up so that a drop of as much as 10.degree. F. in water temperature of the water heater tank of the coffee brewer, will be permitted before the water is reheated. Moreover, many such coffee brewers will dispense heated water into the brew basket at any time, irrespective of the temperature of the water. When coffee is brewed at a higher temperature, more flavor will be extracted from the coffee grounds; whereas, when coffee is brewed at a lower temperature, it will be weaker as the cooler brew water will not extract the maximum amount of flavor from the coffee grounds. This may also affect the shelf life of the brewed coffee, once made. For example, large batches of coffee which are dispensed into a container, such as a thermal container, airpot, or satellite container (all of which are discussed in greater detail hereafter), may have an acceptable shelf life for consumption of up to three hours, or possibly more, if the coffee was brewed at a higher temperature; but if brewed at a lower temperature, the brewed coffee may only have an acceptable shelf life of an hour, or less.
Many current brewers will allow a "double brew". This condition arises if the brew button is pushed a second time after the first brew has been partially completed. The result may be that the coffee carafe or other container into which the coffee is being dispensed may be overfilled and, occasionally, internal overfilling of the coffee brewer apparatus itself may occur.
Coffee brewers are exposed to severe operating conditions and extended service times, reducing the component lifetime of the parts and wasting energy if the brewer is not used during a particular period. Coffee brewers are often plugged in and left running for twenty-four hours per day, three-hundred-and-sixty-five days per year. While not in service--that is, while not actively brewing coffee, or when a brewing cycle is not imminent, such as overnight or on weekends in an office environment--the water in the water heater might be constantly reheated each time the water temperature falls below the lower limits set by the electromechanical thermostat and, therefore, energy is wasted as well as extensive wear on components is caused. The present invention will provide an electronically controlled, microprocessor-based brewing apparatus whereby a number of prior difficulties with former coffee brewers are overcome, and whereby a number of additional features may be provided. Such features will include the ability to choose various volumes for each batch to be brewed, thus permitting the brewed product to be dispensed into a carafe, a thermal container, an airpot, or a satellite container. However, such volume control choice is generally made at the factory, since the external dispensing structure for the beverage brewing apparatus will vary depending on the nature of the container into which the brewed beverage is to be dispensed.
Of course, many other features will be discussed in greater detail hereafter, including significant diagnostic programs that may be built into the microprocessor; the ability to display various instantaneous information concerning the status of the brewing apparatus, water temperature, and so on; the ability to maintain a history of the number of brewing operations per day over a period of time for the apparatus; and a program to determine whether any of the valves controlling water inlet or heated water outlet may be defective.
Particularly where an establishment, including an office, and more particularly including restaurants, coffee shops, donut shops, and the like, is employing the use of a modern beverage brewing apparatus in keeping with the present invention, there must be the ability to prepare large amounts of coffee and other brewed beverages in a relatively short period of time, such as during peak consumption periods, and also randomly at other times. Many such brewing apparatus may be called upon to have a brew volume of up to one-hundred-and-twenty-eight ounces, or more. More specific discussion concerning various brew batch sizes is given hereafter. However, no matter what size the batch may be, the control of water, especially in terms of the amount of water delivered, its temperature, and the rate at which the water is delivered, is of paramount importance. Of course, particularly for retail establishments such as restaurants, coffee shops, and donut shops, it may be desirable to have a number of different varieties of brewed coffee and other beverage available at any one time and, therefore, the use of a single brewing apparatus may require an element of programmability so that different varieties of coffee, for example, may be brewed using the optimum brewing cycle operations for that particular variety of coffee.